The A7N266-VM is an nForce board, a chipset known throughout the land for its absolutely wonderfull Linux support...
Getting back to reality here, if none of the nVidia RPMs for the nvnet LAN driver work (because you're using a newer version of the kernel than they were compiled for) you're left with little recourse but to download the source manually and compile it yourself.
First, grab the latest nForce driver source
tarball and then do the following in a terminal (as root):
Code:
cd /usr/src
tar zxvf /path/to/tarball/NVIDIA_nforce-1.0-0261.tar.gz
cd nforce/nvnet
make && make install
substituting /path/to/tarball for the real path to the tarball. Assuming the compile and install goes without errors (you'll need the kernel source package for the exact kernel you're running for it to work so be sure to grab and install it beforehand) then you should be able use Red Hat's tools to set up and configure the LAN interface.